Fluidic oscillator for a nozzle assembly for enhanced cold performance

ABSTRACT

Provided is a fluidic oscillator circuit for a nozzle assembly configured to generate oscillating sprays of fluid from an outlet of the nozzle assembly and to improve spray performance of fluid having low temperatures or high viscosity. In one embodiment, provided is an interaction region for a fluidic oscillator circuit that includes an apex protrusion shaped to assist with generating vortices within the interaction region. In another embodiment, provided is an interaction region for a fluidic oscillator having a power nozzle that includes at least one finger protrusion that lengthens the power nozzle to create jets of fluid in the interaction region that are less diffused to improve cold performance of the fluidic oscillator circuit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/916,869 filed on Oct. 18, 2019 and titled,“FLUIDIC OSCILLATOR FOR A NOZZLE ASSEMBLY FOR ENHANCED COLD PERFORMANCE”which is incorporated by reference in its entirety.

FIELD OF INVENTION

The present disclosure generally relates to fluidic oscillators andnozzle assemblies and methods of making the same to produce anoscillating flow of fluid therefrom. More particularly, this disclosurerelates to a fluidic oscillator that can operate at the coldertemperatures usually associated with higher viscosity fluids.

BACKGROUND

Fluidic oscillators are well known in the prior art for their ability toprovide a wide range of liquid spray patterns by cyclically deflecting aliquid jet. The operation of most fluidic oscillators is characterizedby the cyclic deflection of a fluid jet without the use of mechanicalmoving parts. Consequently, an advantage of fluidic oscillators is thatthey are not subject to the wear and tear which adversely affects thereliability and operation of other spray devices.

Examples of fluidic oscillators may be found in many patents, includingU.S. Pat. No. 3,185,166 (Horton & Bowles), U.S. Pat. No. 3,563,462(Bauer), U.S. Pat. No. 4,052,002 (Stouffer & Bray), U.S. Pat. No.4,151,955 (Stouffer), U.S. Pat. No. 4,157,161 (Bauer), U.S. Pat. No.4,231,519 (Stouffer) which was reissued as RE 33,158, U.S. Pat. No.4,508,267 (Stouffer), U.S. Pat. No. 5,035,361 (Stouffer), U.S. Pat. No.5,213,269 (Srinath), U.S. Pat. No. 5,971,301 (Stouffer), U.S. Pat. No.6,186,409 (Srinath) and U.S. Pat. No. 6,253,782 (Raghu). Each of thesereferences as well as the references discussed throughout thisapplication below are incorporated by reference herein in theirentireties.

For the spraying of some high viscosity liquids (i.e., 15-20centipoise), the “mushroom oscillator” disclosed in U.S. Pat. No.6,253,782 (Raghu) and shown in FIG. 2 has been found to be especiallyuseful. Raghu describes extensively the theory of operation and itsdimensional characteristics and it has been the dominant productionchoice for a number of years, producing a heavy ended spray distributionwith acceptable cold performance in methanol based fluids at 0° F.However, over the years, the requirements for spray distribution andcold performance have increased, as the temperatures the nozzleassemblies are expected to perform in have dropped and additional fluidbases have been introduced. Methanol based fluids are slowly beingreplaced with ethanol based or isopropyl based fluids. These fluids, atcold temperatures, have significantly higher viscosities than themethanol based fluids of the past. Minor improvements to thefoundational geometry of fluidic oscillator circuits have been proposedand adopted as described in U.S. Pat. Nos. 7,267,290 and 7,472,848. Bothattempt to create additional instability in the jets in higher viscosityfluids, helping the circuit to establish a robust oscillation.

FIG. 1 illustrates an embodiment from U.S. Pat. No. 7,267,290 thatteaches to incorporate a finger like structure behind the dome ormushroom structure in an attempt to create additional instability, avortex, in the feed of the power nozzle. FIG. 2 illustrates anembodiment from U.S. Pat. No. 7,472,848 that has introduced a step atthe exit of the power nozzle, introducing an additional recirculation orvortice in the jet's path creating an instability.

Both of these improvements have produced slightly better cold performingcircuits but have some drawbacks. For example, U.S. Pat. No. 7,267,290requires the circuit to be slightly longer and often this is notallowable within the available packaging space. Also, this configurationmay be difficult to scale for low flow circuits. U.S. Pat. No. 7,472,848has been the most widely adopted of the two, with minor improvements tocold performance but not to distribution. As can be noted, both of thesepatents describe changes to the circuit outside of the interactionregion.

However, it also has been found that as the temperature of such liquidscontinues to decrease so as to cause their viscosity to increase (e.g.,25 centipoise), the performance of this type of oscillator candeteriorate to the point where it no longer provides a jet that issufficiently oscillatory in nature to allow its spray to be distributedover an appreciable fan angle. This situation is especially problematicin windshield washer applications that utilize such fluidic oscillators.

Interaction region modification attempts to improve distribution of thetraditional mushroom circuit have led to U.S. Pat. No. 7,651,036, whichis categorized as a “three jet island” circuit illustrated by FIG. 6 .Here an additional jet and island is introduced to the interactionregion to generate a number of additional vortices and instability. Thethree jet island circuit provides improved cold performance and someimprovement to the evenness of the distribution. While this circuitworks quite well, it does produce some manufacturing challenges. Forexample, as the flow rate of the circuit drops, the size of the internalsmaller third island gets quite small and relatively fragile. The veryact of assembling the fluidic oscillator chip, by pushing the chip intothe slot (FIG. 5 ), can damage the smaller island 34 or even break itoff. As a result, this three jet island circuit can only be reliablyused for relatively high flow rate nozzles, as additional scrap canprovide for unintended resulting spray geometries. Further, the additionof the third flow channel requires that all three flow channels or powernozzles 24 get smaller to keep the flow rates in specification, leadingto a higher risk of clogging. This necessitates additional complexity inthe filter region which has its own manufacturing and packagingchallenges.

Despite much prior art relating to fluidic oscillators, there stillexists a need for further technological improvements in the design offluidic oscillators for use in colder environments. The presentinvention describes additional work that has been performed to improvethe circuit, while eliminating some of the drawbacks described above.

SUMMARY

This disclosure relates to embodiments for a fluidic oscillator circuitfor a nozzle assembly. In one embodiment, provided is a fluidicoscillator circuit comprising a geometry defined in a surface thatincludes at least one inlet configured to receive a flow of fluid. Aninteraction region may be positioned between the at least one inlet andan outlet, said interaction region is defined by a perimeter wall. Atleast one power nozzle may be configured to produce a jet of fluidreceived from the at least one inlet and circulated within theinteraction region. An may be outlet in communication with theinteraction region and be configured to dispense an oscillating spray offluid in a desired spray pattern therefrom. An apex protrusion may bepositioned along the perimeter wall of the interaction region andprotrudes inwardly from the perimeter wall. The at least one inlet mayinclude a geometry that allows for fluid communication with an oppositeside of the surface in which the geometry is defined. The geometry mayfurther include an elongated path from the at least one inlet to thepower nozzle. The interaction region may include a dome or mushroomshaped region defined by the perimeter wall. The geometry may include afirst inlet and a second inlet defined in the surface, the first inletmay be in communication with a first power nozzle and the second inletmay be in communication with a second power nozzle, the first powernozzle and second power nozzle are each configured to produce a jet offluid received from the at least one inlet and circulated within theinteraction region wherein the apex protrusion may be positioned betweenthe first power nozzle and the second power nozzle along the perimeterwall of the interaction region. The apex protrusion may be positioned anequal distance from each of the first power nozzle and the second powernozzle. The apex protrusion is shaped to include an intersection of tworounded or curved perimeter wall of the interaction region thatintersect at a point. The apex protrusion may be shaped to include anintersection of two rounded or curved perimeter surfaces of theinteraction region that intersect at a point and said point is an equaldistance from the first power nozzle and the second power nozzlepositioned along the interaction region. The apex protrusion may beconfigured to direct or stabilize the location of a plurality ofvortices formed by fluid jets from the at least one power nozzle withinthe interaction region for controlling a geometrical placement of thevortices therein, wherein the plurality of vortices includes a leftvortex and a right vortex formed by fluid with an increased measure ofviscosity due to operation in cold temperatures. The first inlet and thesecond inlet may communicate separately to the first power nozzle andthe second power nozzle in which the first power nozzle and second powernozzle are not fed from a common plenum. The outlet may includes anasymmetrical or yawed angle configuration.

In an embodiment, the geometry may include a first inlet and a secondinlet defined in the surface, the first inlet in communication with afirst power nozzle and the second inlet is in communication with asecond power nozzle, the first power nozzle and second power nozzle areeach configured to produce a jet of fluid received from the at least oneinlet and circulated within the interaction region. A set of finger likeprotuberances may be defined adjacent an exit of the first power nozzleand a set of finger like protuberances defined adjacent an exit of thesecond power nozzle, the finger like protuberances are defined along theperimeter wall of the interaction region.

In another embodiment, provided is a fluidic oscillator circuit for anozzle assembly comprising a geometry defined in a surface that includesat least one inlet configured to receive a flow of fluid. An interactionregion may be positioned between the at least one inlet and the outlet,said interaction region is defined by a perimeter wall. At least onepower nozzle may be configured to produce a jet of fluid received fromthe at least one inlet and circulated within the interaction region. Anoutlet may be in communication with the interaction region that isconfigured to dispense an oscillating spray of fluid in a desired spraypattern therefrom. A set of finger like protuberances may be definedadjacent an exit of the power nozzle along the perimeter wall of theinteraction region. The at least one inlet may includes a geometry thatallows for fluid communication with an opposite side of the surface inwhich the geometry is defined. The geometry may further include anelongated path from the at least one inlet to the power nozzle. Theinteraction region may include a dome or mushroom shaped region definedby the perimeter wall. The geometry may include a first inlet and asecond inlet defined in the surface, the first inlet in communicationwith a first power nozzle and the second inlet is in communication witha second power nozzle, the first power nozzle and second power nozzleare each configured to produce a jet of fluid received from the at leastone inlet and circulated within the interaction region. An apexprotrusion may be positioned between the first power nozzle and thesecond power nozzle along the perimeter wall of the interaction region.The geometry may include a first inlet and a second inlet defined in thesurface, the first inlet may be in communication with a first powernozzle and the second inlet may be in communication with a second powernozzle, the first power nozzle and second power nozzle are eachconfigured to produce a jet of fluid received from the at least oneinlet and circulated within the interaction region. The first powernozzle may include a first finger like protuberance that extends from afirst side of the exit of the first power nozzle and a second fingerlike protuberance that extends from a second side of the exit of thefirst power nozzle along the perimeter wall of the interaction region.The second power nozzle may include a first finger like protuberancethat extends from a first side of the second power nozzle and a secondfinger like protuberance that extends from a second side of the secondpower nozzle along the perimeter wall of the interaction region. Thefinger like protuberances act to lengthen the power nozzle by extendinginto the interaction region and be configured to create jets of fluidtherefrom that are configured to reduce likelihood of attachment to theperimeter wall of the interaction region. The first inlet and the secondinlet may communicate separately to the first power nozzle and thesecond power nozzle along the surface in which the first power nozzleand second power nozzle are not fed from a common plenum. The outlet mayinclude an asymmetrical or yawed angle configuration.

DESCRIPTION OF THE DRAWINGS

These, as well as other objects and advantages of this invention, willbe more completely understood and appreciated by referring to thefollowing more detailed description of the presently preferred exemplaryembodiments of the invention in conjunction with the accompanyingdrawings, of which:

FIG. 1 is a front view of a mushroom style fluidic oscillator circuit ofthe prior art;

FIG. 2 is an enlarged schematic view of a fluidic oscillator circuit ofthe prior art;

FIG. 3 is an enlarged view of a fluidic oscillator chip of the prior artwith a plurality of filter posts;

FIG. 4 is a front view of a fluidic oscillator circuit of the prior artwith a yawed configuration;

FIG. 5 is a perspective view of an exploded nozzle assembly and fluidicoscillator chip of the prior art;

FIG. 6 is a front view of a fluidic oscillator circuit of the prior artwith a three jet island configuration;

FIG. 7 is a schematic illustration of an interaction region and vortexlocations for fluid in a fluidic oscillator circuit of the prior art asdescribed in U.S. Pat. No. 6,253,782;

FIG. 8A is a schematic front view illustrating an interaction region andvortex locations for fluid flow of an oscillator circuit of the instantdisclosure;

FIG. 8B is a schematic front view illustrating an interaction region andvortex locations for fluid flow of an oscillator circuit of the instantdisclosure;

FIG. 8C is a schematic front view illustrating an interaction region andvortex locations for fluid flow of an oscillator circuit of the instantdisclosure;

FIG. 8D is a schematic front view illustrating an interaction region andvortex locations for fluid flow of an oscillator circuit of the instantdisclosure;

FIG. 9A is a front view of an embodiment of an oscillator circuit of theinstant disclosure;

FIG. 9B is a front view of an embodiment of an oscillator circuit of theinstant disclosure;

FIG. 10 is an image of a yawed spray from a fluid oscillator circuit ofthe instant disclosure;

FIG. 11 is an image view of an existing spray from a fluid oscillatorcircuit of the prior art;

FIG. 12A is a front view of embodiments of fluid oscillator circuits ofthe present disclosure;

FIG. 12B is a front view of embodiments of fluid oscillator circuits ofthe present disclosure; and

FIG. 13 is a table that illustrates viscosity versus temperature curvesfor methanol and ethanol fluids.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments of thepresent teachings, examples of which are illustrated in the accompanyingdrawings. It is to be understood that other embodiments may be utilizedand structural and functional changes may be made without departing fromthe respective scope of the present teachings. Moreover, features of thevarious embodiments may be combined or altered without departing fromthe scope of the present teachings. As such, the following descriptionis presented by way of illustration only and should not limit in any waythe various alternatives and modifications that may be made to theillustrated embodiments and still be within the spirit and scope of thepresent teachings. In this disclosure, any identification of specificshapes, materials, techniques, arrangements, etc. are either related toa specific example presented or are merely a general description of sucha shape, material, technique, arrangement, etc.

Provided are concepts that modify an interaction region of a fluidicoscillator circuit that are enhancements and are not described or taughtby the prior art. FIGS. 8A-8D illustrate various geometries of a fluidicoscillator circuit 100 that may be defined within a chip to be insertedor otherwise attached to a nozzle assembly. The geometry of the fluidicoscillatory circuit may be defined in the surface of a chip or a surfacewithin a nozzle device. The circuit and surface and/or nozzle device maybe made from a rigid material including polymers or alloys that may beformed in any commercial manner including by molding, additivemanufacturing, or other known methods.

In one embodiment, the fluidic oscillator circuit 100 includes at leastone inlet 110 to receive a flow of fluid and an outlet 120 to dispensean oscillating spray of fluid in a desired spray pattern therefrom. Aninteraction region 130 may be placed between the inlet 110 and theoutlet 120 to allow for a desired fluid communication therethrough. Atleast one power nozzle 140 may be in aligned about the interactionregion 130 to produce a jet of fluid received from the inlet 110 andcirculated within the interaction region 130. The particular geometriesof each of the elements identified that make up the fluidic oscillatorcircuit 100 have been identified to manipulate the flow of fluid thereinto produce a desired shape of an oscillating fluid spray. The inlet 110may have a geometry that allows for fluid communication with theopposite side of the circuit and then an elongated path from the inlet110 to the power nozzle 140.

In one embodiment, the interaction region 130 includes a dome ormushroom shaped region defined by a perimeter wall or surface 132 thatincludes features to further manipulate the flow of fluid therein thatis not known or taught by the prior art. In particular, the interactionregion 130 may include an apex protrusion 150 that is positioned alongthe perimeter surface of the interaction region 130 and protrudesinwardly from the perimeter. The apex protrusion 150 may be positionedbetween two opposing power nozzles 140. The apex protrusion 150 may bepositioned an equal distance from each of the two opposing power nozzles140, such as first and second power nozzles 142, 144 as illustrated byFIG. 8C. The apex protrusion may be shaped to include an intersection oftwo rounded or curved perimeter surfaces of the interaction region 130that intersect at a point. The intersection point may be an equaldistance from the two opposing power nozzles 140 positioned along theinteraction region 130. The intersection point may be aligned along acentral axis 170 as described below.

The apex protrusion 150 may be configured to direct or stabilize thelocation of vortices 160 formed by fluid jets within the interactionregion 130 for controlling a geometrical placement of the vorticestherein. FIGS. 8A and 8C illustrate one possible, and effective,interaction region geometry that includes the apex protrusion 150. Inthis embodiment, there are separate inlets 110 that communicateseparately to opposing power nozzles 140 in which the power nozzles arenot fed from a common plenum. However, this disclosure contemplates thatthe addition of an apex protrusion 150 may be used in various types offluidic oscillator circuit types and may also be employed with othertypes of fluidic oscillator circuits such as those that do utilize acommon plenum for receiving fluid from an inlet.

FIGS. 8A and 8C illustrate the apex protrusion 150 that is now added tothe interaction region 130 to assist with forming left and rightvortices 160 within the interaction region 130 when fluid is introducedtherein from the power nozzles 140. FIG. 7 is provided to identify howfluid flow travels through a known type of interaction region withoutsuch an apex protrusion. Further, FIGS. 8B and 8D are provided for aframe of reference to illustrate how the flow of fluid may bemanipulated by the addition of an apex protrusion 150 (illustrated byFIGS. 8A and 8C) to provide consistency in fluid flow. In particular,the newly disclosed interaction region 130 having the apex protrusion150 is particularly beneficial when a fluid has an increased measure ofviscosity due to operation in cold temperatures.

For example, the addition of the apex protrusion 150 allows for multipleupper vortices 160 along either side of the apex protrusion 150 duringan oscillatory cycle of fluid flow as it is dispensed from the outlet120. This consistency of vortex creation is particularly viewed fromFIG. 8A as the spray of fluid from the outlet 120 is at an angle,compared to FIG. 8C as the oscillation of the spray of fluid from theoutlet 120 is directed outwardly along an axis generally aligned along acentral axis 170 of the circuit 100. Notably, the vortices 160 appear tohave a generally consistent shape of fluid flow during the oscillationcycle as the fluid spray is generated along an entire fan spray shape.

Contrarily, FIGS. 8B and 8D illustrate inconsistent shaped vortices 160wherein a large upper vortex and a small upper vortex exist in FIG. 8Bas the spray of fluid from the outlet is at an angle. Further, FIG. 8Dillustrates inconsistent shaped vortices 160 compared to the interactionregion illustrated by FIG. 8B as the oscillation of the spray of fluidfrom the outlet 120 is directed outwardly along the axis generallyaligned along a central axis 170 of the circuit.

A sample circuit was made with the geometry of the fluidic oscillatorcircuit 100 that includes the apex protrusion 150. It was tested toproduce a nominal fan of about 53 degrees with a uniform spray patternvery similar to the three jet island circuit described above. Its flowrate was about 500 ml/min at 22 PSI. Cold performance was identified tobe quite good in a solution of 50% methanol at 0 degrees F., with a coldfan of 35 degrees at about 5 PSI and 40 degrees at 6 PSI. Notably, asimilar three jet island circuit would have a cold fan of about 30degrees at 7 PSI, 32 degrees at 10 PSI and 40 degrees at 15 PSI. Thisembodiment provides a significant improvement over the prior art asduring the oscillation cycle for a fluid during cold temperatures, thefan recovered much quicker, allowing for a larger nominal fan angle.

In another embodiment, as illustrated by FIG. 9A, provided is fluidicoscillator circuit 100 having much of the similar features as describedabove but now also including an interaction region improvement that hasbeen discovered. This embodiment includes a set of finger likeprotuberances 200 defined adjacent an exit of the power nozzle 140. Thefinger like protuberances 200 may extend from either side of the powernozzle 140 and act to lengthen the power nozzle without increasing theoverall size of the fluidic oscillator circuit or chip. The addition ofsuch finger like protuberances 200 sufficiently lengthens the lumen ofthe power nozzles 140 such that as fluid flows therethrough, jets arecreated that are less diffused (i.e., have less wall attachment). Theproduced jets having a reduced diffusion within the interactions providefor an increase of active/unstable fluid under cold and/or highviscosity conditions. The finger like protuberances 200 may produce astronger jet/flow of fluid in the middle of the interaction region 130.The resultant fluid spray from the outlet 120 was found to be a moreuniform fan than the traditional mushroom shaped interaction regionwithout such finger like protuberances. FIG. 9A shows one possibleembodiment of this feature having an outlet 120 with an asymmetrical oryawed angle configuration and multiple inlets 110. However, thisdisclosure contemplates that the finger like protuberances 200 may beadapted for use in all types of fluidic oscillator circuits that areknown to exist and this disclosure is not limited in this regard.

For comparison, the circuit which is a traditional style mushroom (theone on left hand side of FIG. 12A or 12B) has similar cold performanceas the new circuit (FIG. 9A). However, because the spray pattern of theold mushroom circuit is heavy ended, it is not preferred for someapplications such as rear automotive window spray. The three jet islandcircuit (FIG. 6 ) results in a desirable uniform fluid output spray fanbut lacks in sufficient cold performance and results in even lessdesirable cold performance than the old mushroom circuit.

The finger like protuberance features 200 (FIG. 9A) extend the powernozzle, and in addition to the inlet 110 having a vertical feed (FIGS.8A-8D, 9A and 9B), work to improve the cold performance of the fluidicoscillator circuit. The combination of vertical feed 110 and finger likeprotrusions 200 result in improved cold performance having an output fanspray that is less heavy ended. Further, the apex protrusion 150 (FIG.12B) assists to makes the spray pattern more uniform withoutcompromising the cold performance. It has been identified that a shortdistance between the vertical feed (inlet 110) and exit of the powernozzle 140 was found to help improve cold performance but adds morerisks for manufacturing.

FIG. 9B illustrates another embodiment of the instant application thatincludes finger like protuberances 200 as well as an apex protrusion 150having a throat exit outlet with an asymmetrical yaw angle. Such anangle may be about 15 degrees and this disclosure is not limited to sucha geometry. This particular embodiment provides subtle improvements tothe behavior of fluid in a nozzle assembly to allow for desiredresultant fluid spray and cold performance that reduces “heavy ended”spray fan geometry.

A sample circuit with the finger like protuberances was found in normal(warm) temperatures to produce a fan of about 60 degrees with a flowrate of 735 ml/min at 18 PSI. The circuit was also found to exhibit coldperformance at 0° F. of a methanol fluid, such as a solution of 50%methanol fluid, a fan of 40 degrees at 4 PSI and a fan of 50 degrees at5 PSI in cold temperatures. The circuit was also found to exhibit coldperformance at 0° F. of an ethanol fluid, such as a solution of 50%ethanol fluid, a fan of 40 degrees at 7 PSI and a fan of 50 degrees at 8PSI. While FIG. 9 depicts a yawed spray circuit, it is equallyapplicable to non-yawed circuits. FIG. 4 shows a traditional prior artmushroom type fluidic oscillator circuit with a yawed configuration forcomparison. The circuit of FIG. 4 includes a fan of 60 degrees and aflow rate of 810 ml/min at 18 PSI in normal (warm) temperatures whileits methanol fluid cold performance exhibits a fan at 20 degrees at 20PSI and 40 degrees at 30 PSI.

In this embodiment of the interaction region enhancement, the fluidicoscillator circuit displays an increase in cold temperature performancethat exceeds similar mushroom circuits.

The following images describe the differences in spray distribution anddroplet size between the new configuration (FIG. 10 ) versus a standardmushroom type fluidic oscillator circuit that is known in the art (FIG.11 ). Here the spray fan produced by the fluidic oscillator circuit ofFIG. 10 includes relatively larger droplet sizes having spray fan edgesonly being slightly heavy ended. In contrast, the traditional mushroomstyle fluidic oscillator illustrated by FIG. 11 produces a spray fanwith relatively small droplet sizes with spray fan edges that areconsidered to have significantly heavy edges.

FIGS. 12A and 12B illustrate embodiments of the improved fluidicoscillator circuit designs disclosed by the instant application as theyare distinguished from circuits known in the art. The known circuits NCare illustrated on the left and embodiments of the new fluidicoscillator circuits 100 are illustrated on the right. These fluidicoscillator designs have been identified to improve cold performance ofthe fluidic oscillator circuit to produce a higher velocity and producea more uniform spray.

FIG. 12A illustrates an embodiment that includes a set of finger likeprotuberances 200 defined adjacent an exit of the power nozzle 140. Thefinger like protuberances 200 may extend from either side of the powernozzle 140 and act to lengthen the power nozzle without increasing theoverall size of the fluidic oscillator circuit or chip. As distinguishedfrom FIG. 9 , FIG. 12A illustrates one possible embodiment of thisfeature having an outlet 120 with a symmetrical configuration and asingle inlet 110. However, this disclosure contemplates that the fingerlike protuberances 200 may be adapted for use in all types of fluidicoscillator circuits that are known to exist and this disclosure is notlimited in this regard.

FIG. 12B illustrates an embodiment that includes an apex protrusion 150that extends into the interaction region 130 of the circuit. The apexprotrusion 150 that is now added to the interaction region 130 assistswith forming left and right vortices within the interaction region 130when fluid is introduced therein from the power nozzles 140. Inparticular, the newly disclosed interaction region 130 having the apexprotrusion 150 is particularly beneficial when a fluid has an increasedmeasure of viscosity due to operation in cold temperatures.

FIG. 13 is provided to illustrate that as the temperature of methanoland ethanol fluids drop, their viscosity increases, thus causing theneed to develop improvements to sprays generated by fluidic oscillatorsfor fluids having reduced temperatures and increased viscosities.

Although the embodiments of the present teachings have been illustratedin the accompanying drawings and described in the foregoing detaileddescription, it is to be understood that the present teachings are notto be limited to just the embodiments disclosed, but that the presentteachings described herein are capable of numerous rearrangements,modifications and substitutions without departing from the scope of theclaims hereafter. The claims as follows are intended to include allmodifications and alterations insofar as they come within the scope ofthe claims or the equivalent thereof.

Having thus described the invention, I claim:
 1. A fluidic oscillatorcircuit for a nozzle assembly comprising: a geometry defined in a planarsurface that includes: at least one inlet configured to receive a flowof fluid; an interaction region defined by a perimeter wall having: anoutlet positioned centrally within a downstream portion of the perimeterwall; opposing first and a second power nozzles disposed between thedownstream portion and an upstream portion of the perimeter wall, eachof said first and second power nozzles configured to: i) producerespective jets of fluid received from the at least one inlet and ii)circulate the respective jets of fluid to form a plurality of vorticeswithin the interaction region thereby dispensing an oscillating spray offluid out of the outlet in a desired spray pattern; and an apexprotrusion extends out from the upstream portion and partially into theinteraction region toward the outlet; wherein the interaction region ispositioned between the at least one inlet and the outlet; and whereinthe upstream portion includes a dome shaped region interrupted along amiddle portion by the apex protrusion.
 2. The fluidic oscillator circuitof claim 1 wherein the at least one inlet includes a geometry thatallows for fluid communication with an opposite side of the planarsurface in which the geometry is defined.
 3. The fluidic oscillatorcircuit of claim 1, wherein the geometry further includes an elongatedpath from the at least one inlet to the first power nozzle.
 4. Thefluidic oscillator circuit of claim 1, wherein the at least one inletconsists of a first inlet that is in communication with the first powernozzle and spaced apart from a second inlet that is in communicationwith the second power nozzle.
 5. The fluidic oscillator circuit of claim4, wherein the apex protrusion is positioned an equal distance from eachof the first power nozzle and the second power nozzle.
 6. The fluidicoscillator circuit of claim 4, wherein the apex protrusion is defined bytwo rounded or curved sections protruding inwardly away from the middleportion of the dome shaped region to intersect at a point that is anequal distance from the first power nozzle and the second power nozzle.7. The fluidic oscillator circuit of claim 4, wherein the first inletand the second inlet: i) communicate separately with the first powernozzle and the second power nozzle and ii) are not fed from a commonplenum formed in the planar surface.
 8. The fluidic oscillator circuitof claim 1, wherein the apex protrusion is defined by two rounded orcurved sections protruding inwardly away from the middle portion of thedome shaped region to intersect at a point.
 9. The fluidic oscillatorcircuit of claim 1, wherein the apex protrusion is configured to director stabilize the plurality of vortices and wherein the plurality ofvortices includes a left vortex and a right vortex formed by fluid withan increased measure of viscosity due to operation in cold temperatures.10. The fluidic oscillator circuit of claim 1 wherein the outlet has anasymmetrical or yawed angle configuration.